The approval by the U.S. Department of Agriculture this month for new soy and corn seeds by Dow Chemical is setting off another battle over genetically modified organisms (GMOs).
At issue is whether the extended use of GMOs is creating a new type of "superweed."
These weeds are developing resistance to herbicides, because the GMO seeds can tolerate greater use of certain herbicides and pesticides.
As more herbicides are sprayed, that's created stronger, herbicide resistant weeds on farmland, reportedly costing farmers a billion dollars in lost crops.
"It is a crisis situation," said Neil Harker, a weed ecologist at Agriculture and Agri-Food Canada. "We're losing the effectiveness of herbicide tools against weeds going forward."
"I'm in favor of GMOs, but they should be used judiciously," he said.
Others say the weed infestation is one more reason to avoid GMOs altogether.
"We don't need pesticide-resistant GMOs to control weeds. There are natural ways to fight them," said Bill Freese, a science policy expert at the Center for Food Safety.
"The GMO industry likes to put a warm fuzzy glow on GMOs but we don't see much use for them at all," he argued.
However, farmers like Bill Horan, who has 4,000 acres in northwest Iowa, believe GMO seeds are irreplaceable. "We've used GMO corn seeds for decades and they're a great product," said the 66-year-old Horan. "It's always a battle with weeds but with the new seeds, the pesticides work better," he said.